How accurate is a speed analysis from CCTV and how reliable is “downloaded data?”​

So, I am working on an interesting case, at the moment. Because it is an ongoing case, I do not want to include specifics, but I have something to share.

The basic merits involve a driver that was driving a very unique German Sports Car that is one of only 10 in the world. He was driving one night and ended up colliding with the rear of a parked police vehicle. No one died and there were no serious injuries, but the police vehicle (with two occupants) rolled over.

The spot where the collision occurred is a well-known illegal street racing hotspot, so obviously there was suspicion (and even a claim) that the driver was racing, when this happened.

The insurer promptly appointed an expert who downloaded the “digital data” from the vehicle and who declared that the speed of the vehicle was 197 Km/h (123 mph), from “last equal wheel rotation.” Obviously, the driver’s insurance claim was repudiated.

But the crash was recorded on a CCTV Camera and the footage was available. I was supplied with all the available evidence and investigated the collision, the vehicle, and the police vehicle along with the scene. I found very little damage – nothing near what you’d expect to see, when a vehicle traveling at that speed would have collided with the rear of a stationery vehicle, so I started to look at the video evidence.

In the video, you could clearly see the vehicle approach, lose control, and collide with the rear of the police vehicle, but it seemed to be a very low speed collision. Both vehicles moved less than 10m (30ft), after impact.

I then asked the driver to go to the same place and to drive a visible exemplar vehicle, in the same direction as on the night of the collision, at exactly 60 Km/h (37.5 mph), to get the footage from the same camera and to send it to me.

Using known fixed objects on the scene (two trees), I would then be able to determine the speed of the vehicle on the night of the collision, by using the known speed and time (from video) of the test vehicle and comparing those results. To my surprise, the calculations of the test vehicle (based on known distance over time) resulted in a speed of 66.67 Km/h and not 60 (41.67 mph and not 37.5) as requested.

I then wrote back to the driver and asked if it was 100% certain that the test vehicle was being driven at 60 (37.5), as I requested. The driver then sent me a video, taken inside the vehicle, as confirmation. To my surprise, the speed was displayed as 70Km/h (43.75 mph) – indicating a very close match, considering natural over-reading of vehicle speedometers. The image with this article was taken directly from that video recording.

For the record, the same Video Analysis of the vehicle that was involved in the collision actually yielded an even lower speed than that of the test vehicle. But I cannot reveal more detail, at this stage.

So – since we know we can trust the speed calculation done from the video evidence, how reliable or scientifically accurate was that “data download?” Makes you wonder, right?

Leave a Comment